Elastic-fluid turbine



Patented Nov. 2 7, 1923. .u

UNITED -STATES V1,415,212 PATENT oFi-'ici-z.

GLENN B. WARREN AND HARRISON L. WIRT, 0F SCHENECTADY, NEW YORK, AS- SIGNORS T0 GENERAL ELECTRIC COMPANY, A CORPORATION 0F NEW YORK.

l ELASTIC-FLUIC TURBINE.

Application med July i2,

Improvements in Elastic-F luid Turbines, of

which the following is a specification.

The present invention relates to elastic fluid turbines of the impulse type and particularly to nozzles for such turbines. As is well understood, the nozzles are stationary, fluid-directing elements which serve to expand the elastic fluid, thereby converting pressure into velocity, and .direct it against the adjacent bucket ring of the 'rotating In general, the nozzles arm-formed guide blades or partitions between two ra ially spaced oo n- -centric rings,'the structure as a whole beingtermed a nozzle diaphragm'. The nozzles may extend entirely around the diaphragm providing for complete peripheral admission or they may extend only part way around.

'In multi-stage turbines of considerable size, the length of the buckets of successive stages increases quite rapidly especially in the last stages and this requires that, elas-` tic fluid leaving one ring of buckets must be expanded radially before being vdirected to the next ring of buckets inorder that the elastic fluid may strike the next ring of buckets throughout their lengths. In other words, it requires that the nozzle passages increase in radial depth from their entrance edges to their exit edges in order to convey the elastic fluid from the shorter ringy of (buckets to the next longer ring of buckets.

Such n'ozzles are ordinarily termed flared nozzles and are well knownin connection with turbines of thisgeneral type. vWith such nozzles, it has been found that the elastic fluid in flowing through them does not discharge in .a perfectly1 axial direction butv that it discharges at anangle to the axial sov that instead of striking the buckets at a right angle, a thin which is desirable in order -to obtain the highest efficiency, it strikesrthe buckets at an angle other than a right angle. In other words, the elastic fluid issuing from the nozzles has a considerablecomponent in a/ radial direction.

The object of our invention is to provide an improved nozzle structure or nozzle diaphragm structure wherein with nozzles of 1922. Serial No. 574,386.

the flaring type the elastic fluid will be discharged in a truly axial direction, and\for a consideration of what we believe to be novel and our invention, attention is directedto the accompanying description and the claims, appended thereto.

. In the drawing, Fig. 'l is a side elevationof a portion of a nozzle dia liragm embodyy ing our -invention, the view eing taken looking 'toward the discharge side of the diaphragm; and Fig. 2 is a sectional view taken on an irregular section between two of the nozzle partitions.

Referring to the drawing, 5 indicates a nozzle diaphragm having nozzle partitions 6. The entrance edges of the nozzle partitions `are designated 7 and the discharge edges 8L The bucket wheels of the stages pfeceding and following diaphragm 5 are indicated aJt 9 and 10, and as will be noted the buckets of wheel 10 are substantially longer than those of wheel 9, which require that the nozzle passages increase in radial depth from their admission to their exit edges, as shown particularly in Fi 2, in order to direct elastic'fluid to the uckets of wheel 10 along their entire length. The foregoing may be taken as typical of a diaphragm between. two successive stages and y'the wheel structures of such stages. As is fixed to the turbine shaftA and carrying'Y the v bucket rings on their peripheries, and the diaphragm comprises a web portion having an opening througli'which the shaft passes anda ring surrounding the web portion between which and the web portion the nozzle partitions are arranged. In general, noz- -4 zle diaphragms are formed in upper and lower halves to facilitate assembling.

As already stated, elastic fluid' in flcwing through flared nozzle lpassages acquires a component in a radial direction and according to our invention we so shape or form'the nozzles that .there will be produced by theml a second radial component which is opposed to that due to the flared nozzle and which 'willneutralize or substantially neutralize it,

whereby the resultant will be a discharge of elastic fluidfrom the nozzles substantially perpendicular to the buckets. We have found thatelastic fluid in passing through a ynoz'zle tends to discharge at a right angle to the' throat or narrowestv cross sectional area iii of the nozzle and according to our invention we so shape the nozzle that the plane of such throat or cross sectional area instead of being radial extends at an angle to the radial, the plane of the throat making such an angle with the radial that it tends to produce a radial component in the elastic fluid flow` of suoli magnitude and direction as to neutralize or substantially neutralize the radial component in the elastic fluid flow which the flaring of the nozzle tends to create. The result is that the elastic fluid issuing from the nozzles is given a direction so it strikes the buckets at a right angle.

Referring now particularly t0 the draw ing, we have illustrated a nozzle structure in which the throat or narrowest cross section occurs at the exit edge of the nozzle, and the desired angle with the radfal is given to the throat by making the exit edges 8 of the nozzle partitions extend at an angle to the radial. This is particularly shown in Fig. l where the dotted line a is radial and the angle b represents the Iangle which the throat makes with the radial.

V ewed from one aspect it may be consid.

ered that the nozzle partitions have been tilted forward from the radial several de'- Acenter of the diaphragm. Accordingly, the

throat of the nozzle is tilted in a direction toward the center of the diaphragm so as to Vproduce a'. component in the elastic fluid fioW toward the center.

n accordance with the provsions o f the patent statutes, We have described the principle of operation of our invention together with the structure and arrangement which we now consider to represent the. best 'ema bodiment thereof, but we desire to have it understood that the structure and arrangement shown is only illustrative and that the invention may becarried out by such other means as come within the scope of the appended claims.

component which the fiared nozzle-passage tends to create.

2. A diaphragm for elastic fluid turbines in which the nozzle passages flare in a radial direction, characterized yby the factl that the nozzle partitions are so shaped that the throats of the nozzles stand at such an angle to the radial that they tend to give to the elastic fiuid fiowing through them a radial component opposed to that which the fiared nozzle passage tends to create.

3. A diaphragm for elastic fluid turbines in which the nozzle passages Hare radially outward characterized by the fact that the nozzle throats stand at such an angle to the radial that they tend to `d'scharge elastic fluid in a direction having| a component toward the center of the diaphragm.

4. A nozzle diaphragm having radially flared passages, and nozzle partitions hav; ing discharge edges which stand at an angle to the radial to provide nozzle throats which tend to discharge elastic fluid at an angle to the axial opposed to the angle tothe axial at which the flared passage tends to discharge elastic fiuid.

5. A nozzle diaphragm having radially outwardly flared passages and nozzle partitions which provide discharge throats inclined toward the center of the diaphragm.

6. A. nozzle diaphragm having radially outwardly flared passages and nozzle partitions having their discharge edges inclined toward the center of the diaphragm.

7. A nozzle diaphragm having radially voutwardly flared nozzle passages the throats of which occur at the discharge edges of the nozzle partitions, said discharge edges being inclined toward the center of the diaphragm.

In witness whereof, `We have hereunto set our hands this 11th day of July, 1922.

GLENN B. WARREN. HARRIsoN L. WIRT. 

